This invention relates in general to radiant heating systems using heated fluid which is pumped through radiant tubing extending in the floor area of the space that is to be heated. More particularly, the invention relates to a radiant heating system that is specifically constructed for installation on top of a subfloor and to a method of installing the system.
Radiant heating has achieved considerable popularity for the heating of buildings. Traditionally, radiant heating tubing has been installed in concrete slabs, in thin slabs applied to frame floors, or under subflooring between the flooring joists. Heated fluid is pumped through the tubing and transmits heat to the floor area and in turn to the space above the floor. The types of tubing installations that have been used in the past are generally satisfactory. However, there are many instances when it is desirable to install a radiant system on an existing floor. This can create significant problems in that it can reduce the height of the room and can adversely affect many existing parts of the building, including toe space beneath cabinets, door clearance at the bottom, built-in appliances, and trim on the perimeter of the floor.
Wooden panels or composite insulation panels having grooves for accepting radiant tubing have been used as structural components in subfloors. However, the panels must retain adequate structural integrity, so the grooves cannot extend too deeply into the panels and the panels must be oriented so that the grooves are installed perpendicular to the structure supporting the floor joists. This can make the pipe layout very difficult and complex. A second type of non-structural panel is sometimes installed on top of a slab or structural wood subfloor. In addition, the outside diameter of the tubing is limited to the groove depth, and this limitation in the tubing size limits the flow rate. The transmission of warmth to the room is limited as well unless an expensive oversized pump is used to circulate fluid through the tubing.
Further, the tubing fits closely in the grooves so that it rubs against the sides of the grooves and creates an undesirable clicking rubbing noise whenever the tubing thermally expands as the system cycles. This noise problem can be severe. Also, some systems require adhesives, or silicon caulks to hold the tubing in the groove in an effort to alleviate the noise problem, and this significantly increases the cost and difficulty of the installation.
The present invention is directed to an improved radiant heating system that can be installed on an existing subfloor while minimizing the thickness that is required to be added on top of the subfloor. It is a particular feature of the invention that the entire thickness of the added sleeper members is available for the tubing, so the tubing diameter is maximized for efficiency in the transfer of warmth to the room that is being heated.
In accordance with the invention, two sides or ends of a room are provided with special wooden header panels that are constructed to accommodate curved bends in the radiant tubing. Spaced apart wooden sleepers are secured to the subfloor that run between the header panels. The sleepers provide parallel channels between them that receive straight runs of the radiant tubing. The channels are considerably wider than the tubing diameter so that the tubing can thermally expand and contract without rubbing against the sleepers and creating unwanted noise. The sleepers and channels are overlaid with heat conductive sheeting such as aluminum panels that have a clearance with the underlying tubing to avoid rubbing between the tubing and the sheeting.
The header panels have arcuate cutouts that are initially occupied by break away header plates that have the same shape as the cutouts. The header plates can be detached so that the tubing can be bent, inserted in the cutouts, and pressed against curved surfaces to provide curved paths for the radius bends of the tubing. Ledges projecting from the curved surfaces hold the bent tubing in place until the header plates can be inserted back into the cutouts and screwed to the subfloor. This permanently secures the tubing against the curved surfaces of the cutouts. The header plates have undercuts that allow them to be pried loose from the headers with a screw driver or other simple tool to facilitate their detachment from the header panels.
The invention is further characterized by the use of holding blocks that secure the tubing in place at strategic locations, where it would otherwise be dynamically stressed by thermal expansion and contraction, such as where the tubing emerges from the floor and where it extends back down through the floor. The holding blocks pivot closed on the tubing and fit closely in the channels. A beveled surface on each block has a predrilled hole that allows the block to be secured to the floor with the screw head recessed below the top surfaces of the sleepers and headers.
Other and further objects of the invention, together with the features of novelty appurtenant thereto, will appear in the course of the following description.